1. Field of the Invention
This invention relates to a fiber-reinforced, plastics article of manufacture which has a noncircular cross section and which is of a multi-chambered, cellular construction and to a method for manufacturing such article.
2. Description of the Prior Art
Fiber reinforced plastics are well known and used for many purposes. Typically, the reinforcing fiber used is a woven fabric that is applied over a mold and coated with a bonding resin. Some special application tools have been developed in which the fibers are applied as chopped strands embedded in a resin and this method obviates much of the labor required when woven fabrics are used. In both of these applications, however, the ultimate strength of the reinforcing fiber is not achieved in the final product.
There is a continuous-filament winding process that has been employed for the manufacture of articles of circular cross section to obtain very strong and lightweight products. This process has been typically employed for the fabrication of pressure vessels and generally comprises winding continuous filaments of a fibrous reinforcing material about a mandrel in circumferential or helical windings to form a plurality of layers of filaments with the windings of the filaments in adjacent layers being diagonally oriented. The filaments are embedded with a bonding resin which is then cured to cement the product into a rigid, strong vessel of a circular cross section.
Recent modifications of this process employing a flexible and inflated mandrel have achieved the fabrication of very strong, lightweight, hollow products having non-circular cross sections. It is desirable in such manufacture to incorporate ballast and strength-imparting members in such a fashion that these members become an integral portion of the final article of manufacture. It is also desirable to provide some means for the attachment of the article of manufacture to other supporting structure.